1. Field of the Invention
The present invention relates generally to cutting tools, and more specifically to a hand tool for cutting circular blanks of material from a larger sheet. The present tool does not penetrate or damage the center of the blank, and is particularly well suited for cutting patches of material for quilting or other purposes where it is essential that the blank not be damaged in any way.
2. Description of the Related Arts
Certain types of quilting involve the assembly of a series of circular components to form a completed quilt. These circular patches or sections of material are stitched together at adjacent points about their circumferences where they are in contact with one another at final assembly. These circular blanks or components must be cut from a larger sheet of material, in order to supply the required materials for forming such a quilt. While it is possible to cut such blanks by hand using scissors, the work is tedious considering the continuous curved cuts which must be made, and the number of such cuts which are required to provide the large number of circular cutouts necessary for the construction of a quilt.
While devices for making circular cuts have been developed in the past (e. g., fly cutters and the like, etc.), such devices generally form a pilot hole through the material being cut, in order to center the cutter precisely in the material being cut. If the blank is to be discarded, with the purpose of the circular cut being only to provide a circular hole in a sheet of material, then the forming of a pilot hole through the discarded material is of no consequence. However, the forming of a pilot hole through the circular blank is unacceptable in the construction of a quilt, and in various other circular articles which may be needed in other fields as well.
Accordingly, a need will be seen for a hand tool for making circular cuts in fabric and/or other relatively light sheet materials (thin plastic, paper, etc.), without requiring the formation of a pilot hole through the center of the circular blank being cut. The present tool is also adjustable to provide a relatively wide range of diameters for circular blanks being cut therewith, as well as other advantages over earlier tools for making circular cuts. While the present tool is particularly adapted for cutting unbroken circular blanks from fabric material for quilting, it is also readily adaptable for cutting unbroken circular blanks from other materials and for other purposes, as well.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
Essentially, the related art of which the present inventor is aware may be divided into two broad categories, with one category comprising tools and devices which do not penetrate the material being cut, and another category comprising devices which centrally penetrate the material being cut in order to provide a pilot hole for guidance of the tool. Such centrally penetrating tools are relatively far removed from the present circular cutting tool, and are only listed further below with no further discussion of their differences and distinctions from the present invention.
The other category of circular cutting tools includes those tools which do not centrally penetrate the subject material being cut, so that the cut circle of material remains unbroken across its surface and may be used for various purposes (patches, covers, etc.). The tools of this class which are known to the present inventor are described in the following patents and publications:
U.S. Pat. No. 3,621,574 issued on Nov. 23, 1971 to Gerald F. Yanke et al., titled "Photographic Print Circle Cutter," describes a circular cutter in which the disc shaped body of the device has a centrally disposed arm extending therefrom. The arm rotates relative to the body of the device, unlike the present circular cutting tool in which the body and arm both rotate as a unit. In the present tool, the cutting blade mounting bracket is the only component of the arm which is radially adjustable, whereas in the Yanke et al. tool, the arm comprises two relatively telescoping components, with the outer portion being adjustably extendible relative to the pivotally mounted inner portion. Moreover, Yanke et al. utilize an injector type razor blade for their cutting element, rather than a rotary blade as used in the present circular cutting tool.
U.S. Pat. No. 4,426,781 issued on Jan. 24, 1984 to Fred Kufrin, titled "Cutter For Making Paper Discs," describes a device having two concentric discs, with a cutting element adjustably disposed within the inner disc. The outer disc remains stationary during cutting operations to bear against the material being cut, while the inner disc rotates with the cutting element; no separate adjustable radial arm is provided by Kufrin, as provided in the present circular cutting tool. Moreover, Kufrin provides only two blade positions to cut only two different diameters of circles with his cutter, while the present tool provides essentially infinite adjustment between its innermost and outermost limits. Kufrin uses a planar blade as a cutting element, while the present tool utilizes a rotary cutting blade. In addition, the interior of the Kufrin tool is open, while the center of the present tool includes a pad which bears against the material being cut to hold it in place during the cutting operation, while the disc, arm, and cutting blade assembly rotate relative to the central pad and material being held in place by the pad.
U.S. Pat. No. 4,593,467 issued on Jun. 10, 1986 to Tibor Safar, titled "Circular Cutter," describes a machine tool (not a hand tool, as in the present circular cutter) for cutting washers, discs, etc. using a drill press, milling machine, or other suitable power tool to drive the device. The Safar tool essentially comprises a generally enclosed housing with an upper central passage just large enough for passage of a rotary shaft therethrough for rotating the arm with its cutting elements. The bottom of the housing comprises a removably attached disc with a central opening therein for clearing the rotating cutting blades. Safar states that it is preferable to provide a series of different lower discs with different opening diameters, so a disc may be selected which fits closely about the diameter of the cutting circle. This entails removing the disc each time the cutting circle diameter is to be changed, as the cutting arm is internal within the housing, rather than being exposed atop a pressure disc, as in the present cutting tool invention.
U.S. Pat. No. 5,014,436 issued on May 14, 1991 to Vincent T. Kozyrski et al., titled "Circle Cutting System," describes a glass cutter having a stationary center component for bearing against the glass, with a relatively rotary arm extending therefrom. No central rotary disc is provided by Kozyrski et al. for bearing against the material being cut, as provided in the present invention. Moreover, the Kozyrski et al. cutting elements are disposed externally at the end of the rotary arm, whereas the single cutting element of the present invention is internally disposed in the adjustable arm channel of the disc, and concealed beneath the adjustable arm. Thus, the cutting element of the present tool is not exposed and cannot make contact with anything or anyone other than the material disposed therebelow for cutting, unlike the exposed cutting elements of the Kozyrski et al. device.
U.S. Pat. No. 5,860,217 issued on Jan. 19, 1999 to the present inventor, titled "Material Circle Cutter," describes a circular cutter having a plurality of radially disposed rotary cutting blades. In one embodiment, the blades are circumferentially disposed and are not radially adjustable to cut different sizes of circular areas. In another embodiment, the rotary blades are disposed through slots in a base, and may be lifted from the slots for placement in different slots of different diameters in order to provide for the cutting of circular patterns of different diameters. The remainder of the mechanism, including means for lifting the blades from the slots in the base, means for urging the blades downwardly during the cutting operation, and means for adjusting the blades radially for different cutting diameters, rotate relative to the base which remains stationary relative to the material being cut. In contrast, the base of the present cutting tool rotates, along with a radially disposed arm across the base which contains a single radially adjustable rotary cutting disc.
U.S. Pat. No. D-393,196 issued on Apr. 7, 1998 to Sonja Klotz, titled "Radial Cutter," illustrates a design having a single arm apparently supported by a suction cup or the like during use. No central rotary disc is apparent in the Klotz design. Moreover, no radially disposed channel for holding a radially adjustable cutting arm therein is apparent in the Klotz design, which features are a part of the present circular cutting tool invention.
U.S. Pat. No. D-409,630 issued on May 11, 1999 to Robert W. Cornell et al., titled "Circle Cutter," illustrates a device having a relatively thick body portion with the arm containing the cutting element apparently telescoping through the body, rather than being disposed within an open channel above a relatively thin and flat disc, as in the present circular cutter tool. No mechanism is apparent in the Cornell et al. design for adjusting the span of the cutting element, nor for providing for rotation of the cutting arm and other components relative to a fixed central hub portion bearing against the material being cut, which means are a part of the present circular cutting tool invention.
German Patent Publication No. 2,910,642 published on Sep. 18, 1980 to Nippon Tenshashi Co. Ltd. describes (according to the English abstract) a tool having a relatively thick body through which a radially disposed arm passes. The arm has a cutting blade disposed at its distal end. A concentrically disposed holder pad is pressed against the underlying material to hold it in place during cutting operations, with the remainder of the tool being rotated to rotate the arm for cutting a circular patch of material. The body of the device is ribbed, and cannot provide unbroken pressure to essentially the entire area of the material being cut, as provided by the present tool. The central hub which is used to apply pressure to the holder pad is secured by a threaded shaft, as is the radial adjustment for the cutting blade. Such adjustments are tedious and are not required for the routine cutting operations for which the present tool provides.
Finally, British Patent Publication No. 2,043,519 published on Oct. 8, 1980 to Nippon Tenshashi Co., Ltd., titled "A Circle Cutter For Cutting A round Piece From A Sheet Material," describes a device apparently identical to that of the '642 German Patent Publication cited immediately above. The same differences and distinctions between that device and the present invention, are seen to apply here as well.
Tools which penetrate the area of the material being cut are not suitable for providing an undamaged blank of material for use in the manufacture of an article, but rather are directed to making a hole in an article, with the material cut from the hole being discarded. Those penetrating circular cutting tools which damage the material being cut are only listed below, as no further detailed discussion of their differences and distinctions from the present invention is required. These centrally penetrating circular cutting tools comprise:
U.S. Pat. No. 1,423,828 issued on Jul. 25, 1922 to Maurice A. Butterfield, titled "Circle Cutting Tool;"
U.S. Pat. No. 2,066,381 issued on Jan. 5, 1937 to Frans O. Albertson, titled "Disk Tool;"
U.S. Pat. No. 2,230,400 issued on Feb. 4, 1941 to Alessandro Cadirola, titled "Revolving Circular Sheet Cutting Device;"
U.S. Pat. No. 3,456,346 issued on Jul. 22, 1969 to John M. Snyder, titled "Circle Cutter And Protective Cover;"
U.S. Pat. No. 3,934,343 issued on Jan. 27, 1976 to Jacek Witecki, titled "Device For Cutting Circles;"
U.S. Pat. No. 4,173,913 issued on Nov. 13, 1979 to Barrie F. Nicholson, titled "Hole Cutter Having Rotatable Blade Carrier;"
U.S. Pat. No. 4,645,390 issued on Feb. 24, 1987 to Ernst Pecha et al., titled "Cutting Tool For Making Holes;"
U.S. Pat. No. 4,782,730 issued on Nov. 8, 1988 to John Picone et al., titled "Straddling Gasket Cutter;"
U.S. Pat. No. 5,079,843 issued on Jan. 14, 1992 to Joseph A. Shelton et al., titled "Hole Cutter For Ostomy Adhesive Wafers;"
U.S. Pat. No. 5,895,183 issued on Apr. 20, 1999 to Jamie McDaniel et al., titled "Circular Hole Cutter;"
U.S. Pat. No. D-375,034 issued on Oct. 29, 1996 to David G. Bowser, titled "Sandpaper And Fibrous Material Cutter;" and Swiss Patent Publication No. 119,286 published on Jul. 1, 1927 to H. Weibel.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.